and there's nothing more important than a nurturing environment with a coach and some dedicated cheerleaders get you through some of the humps. >> among the new recommendations help -- >>> this weekend, a quarter of the nfl quarterbacks who took the field left with concussions. doctors, trainers and coaches have started paying closer attention to the cumulative brain injuries sustained from concussion and what they mean not just for the pros but for our kids. passionate about staying in the game. football is america's sport. and christian stevenson's 12- year-old son is enamored with it. >> he gets up two hours before practice, he's got his uniform on. he can't walk when he gets off the practice field because they've worked him so hard but he's smiling. >> her experience has been far different. after suffering repeated concussions playing the game he loved, he knew it was time to quit. >> my memory is still kind of off. >> because of growing concerns that some of the damage from repeated concussions doesn't go away, one leading boston researcher proposed very tough guidelines for the younges